Trenching machine



April 1, 1958 w. D. BROWN 2,828,557

TRENCHING MACHINE Filed Nov. 25, 1955 4 Sheets-Sheet 1 INVEN TOR.

A ril 1, 1958 w. D. BROWN TRENCHING MACHINE 4 sheets sheet '3 Filed Nov.25, 1955 IN V EN TOR. 1M Jmm "K W M 1% J w o 0 m w j o 7 M j m .y ir 0.a w a Q a m 6 A o a 0 0 0 97 z .3 6 O 3 9 Q 6. a a 4 O o o a A o A 7 M 4M? V@ o 5 Mmm 4 w z o W w \J ix 1- HR. r Z. L..\ 4 W WWW i .l! 1 W oApril 1, 1958 w. D. BROWN TRENCHING MACHINE 4 Sheets-Sheet 4 Filed Nov.25, 1955 INVENTOR.

Z/Zawzz A477 ilnitcd States Patent 8 i TRENCEHNG MACHlNE William DelbertBrown, Woodbine, Iowa Application Novem er 25, 1955, Serial No. 548,838

8 tilaims. (Cl. 37-90) This invention relates to a trenching machineand, more particularly, to a portable self-contained trenching machinewhich is of relatively simple construction.

In the past, trenching machines have been substantial devices and mostcommonly involved the use of some form of vehicle, such as a tractor orthe like. As may be readily appreciated, this constituted a complexmechanism and, because of this, required a substantial investment.

An object of this invention is to provide a relatively simplyconstructed portable trenching machine which is entirely self-contained.

Another object of the invention is to provide a portable trenchingmachine the use of which is economically feasible by various tradeswherein a narrow deep trench is required and which may be easily partlydisassembled to enable movement on a small truck such as a pickup truckfor transporting between jobs.

Another object of the invention is to provide a portable trenchingmachine having a boom extending from one end thereof and handle membersextending from the other end thereof, both of which may be readilydetached so as to substantially reduce the length of the machine.

A further object of the invention is to, provide a portable trenchingmachine having a power source carried thereon with common drivemechanism for moving the machine at a trenching rate when a trench isbeing dug or at a mobile rate when a trench is not being dug, said meansincluding a drive pulley which may be directly connected to the drivefor the wheels of the machine in mobile rate movement and may beindirectly connected to the wheels when in trenching rate movement.

A further object of the invention is to provide a pair of spaced-apartside plates forming a body for a trenching machine, a pair of boomplates lying adjacent the side plates and pivotally mounted thereon,means connected between the side plates and the boom plates for pivotingthe boom plates and the boom carried thereon with respect to the body,propelling members carried beneath the boom at the end thereof adjacentthe body for piling up and throwing outwardly material coming up fromthe trench, a pair of paddle-carrying chains mounted on the boom platesand carried outboard of the propelling members to transport materialaway from the propelling members, and an endless cutter chain extendingaround the boom and by connections with drive sprockets causingmovementof the propelling members and the paddlecarrying chains.

Still another object of the invention is to provide a trenching machinehaving a forwardly-extending threaded stub shaft upon which an end of aboom, may be slidably mounted, an endless chain extending around theboom, a drive sprocket on the body of the machine, and a nut threaded onthe stub shaft and engageable with said boom to, shift the boomoutwardly on the stub shaft to tension the, endless chain, the chainholding the boom on the stub shaft, and also permit movement of the boomalong r 2,828,557. Patented Apr. 1:, 1.95.8

the stub shaft in the opposite direction to slack the chain so that itmay be removedfrom the boom and thus permit removal of the boom from thestub shaft.

Another object of the invention is to provide a portable trenchingmachine having a body formed of a pair of elongated side plates whichare connected together by cross braces in the form of tubular rods whichalso flmction as supports for the front and rear axle bearings and adrive shaft extending transversely of the machine, and motor supportbrackets connected between the upper edges of said side plates at oneend thereof for supporting a motor, the foregoing parts forming thestructural frame or body of the machine.

Another object of the invention is to provide a portable trenchingmachine as defined in the preceding paragraph, wherein said drive shafthas a ratchet wheel and a drive sprocket secured thereto, an oscillatingpawl carrier adjacent the ratchet wheel and having a drive pawl, a holdpawl positioned on said pawl carrier to have no throw when the carrieroscillates, a manually-operable control member pivotally mounted on thebody for movement between a plurality of positions and having armsengageable with said pawls to permit both pawls to engage with theratchet wheel or permit only the hold pawl to engage the ratchet wheel,or to hold both pawls away from the ratchet wheel and wherein anotherdrive pawl may optionally be used with said first drive pawl so as toindex the ratchet wheel in both directions of movement of the pawlcarrier to double the trenching rate of ma chine movement, and anotherarm on the control member engageable'with said second drive pawl todisengage said second drive pawl from the ratchet wheel whenever saidfirst drive pawl is disengaged.

Still another object of the invention is to provide a trenching machinehaving a boom, an endless cutter chain extending around the boom and aguide sprocket at the free end of the boom, and a deflector positionedadjacent the guide sprocket for deflecting rocks or the like which thechain may be carrying toward the sprocket so that they may not jambetween the chain and sprocket.

The objects of the invention generally set forth, together with otherancillary advantages, are attained by the construction and arrangementshown by way of illustration in the accompanying drawing, in which:

Fig. 1 is a side elevation of the portable trenching machine with theforward end thereof at the right of the figure and with boom up so as topermit mobile movement of the machine;

Fig. 2 is a side elevation of the machine and ofthe side opposite tothat shown in Fig. 1 with the rear of the machine to the right of thefigure and with the parts shown in trench cutting position;

Fig. 3 is a fragmentary enlarged plan View of the boom outer end with aportion of the cutter chain broken away;

Fig. 4 is a fragmentary enlarged side elevation similar to that of Fig.l with the nearest wheels removed;

Fig. 5 is a fragmentary enlarged vertical section taken along the line5--5 in Fig. 6.;

Fig. 6 is a fragmentary enlarged plan view of the.

trenching machine; I Fig. 7 is. a generally vertical section on anenlarged scale taken along the line 7--7 in Fig. 5;

Fig. 8 is a fragmentary enlarged vertical sectiontaken along the line8-3 in Fig. 7;

Fig. 9 is an enlarged vertical section taken along the line 9-9 of Fig.6;

Fig. 10 is an enlarged vertical section taken. along the line Ill-4t? ofFig. 6; and,

Fig. 11 is a fragmentary enlarged vertical section taken along the line1111 in Fig. 2.

While this invention is suceptible of embodiment in many dilferentforms, there is shown in the drawings and will herein be described indetail an illustrative embodiment of the invention with theunderstanding that the present disclosure is to be considered as anexemplification of the principles of the invention and is not intendedto limit the invention to the embodiment illustrated. The scope of theinvention will be pointed out in the appended claims.

As shown generally in Figs. 1, 2 and 6, the portable trenching machinehas a body formed of spaced-apart elongated side plates 1 and 2 whichare interconnected by cross braces in the form of tubular rods. Thesecross braces are indicated at 3 and 4. The cross brace 4 receives afront axle 5, and a similar cross brace 4a receives a rear axle 6. Thesecross braces surround openings (not shown) in the side plates 1 and Zand may be secured to the side plates by suitable means such as Welding.The cross braces for the front and rear axles, one being shown at 4,form housings for bearings 7 (Fig. A wheel 14 is mounted at the outerends of each axle.

The rear ends of the side plates 1 and 2 have brackets 11 afiixed to theouter sides thereof which slidably receive handles 12 and 13 and thehandles may be removably connected to the body by suitable mechanismssuch as cotter pins extended through the handle members.

A pair of brackets 15 and 16 extend transversely between the side plates1 and 2 at their rear upper edges and have a pair of laterally-spacedrods 17 upon which a motor 18 may be slidably mounted. The motor 18 hasa pair of drive pulleys, one of which is shown at 19, for driving belts20 and 21 which drive a double-grooved pulley 22. A handle 25 ispivotally mounted on the bracket 16 and by connections to the motormounting may be used to engage or disengage the drive to the pulley 22by controlling the tightness of the belts 2i) and 21.

The pulley 22, as shown in Fig. 9, is connected to a sleeve 26 rotatablymounted on a drive shaft 27 which extends through the cross brace 3. Thesleeve 26 has a sprocket 30 formed integrally thereon which drives achain 31 which is in driving engagement with a sprocket 32 fixed toanother drive shaft 33 extending transversely of the body. An idlertensioning sprocket 34 is adjustably mounted on a bracket 35 fixed tothe side plate 2.

The drive shaft 33 outboard of the side plate 1 has an eccentric pin 36connected thereto which drives a crank rod formed of parts 37 and 38which are adjustable with respect to each other. The upper end of thepart 38 is connected by a pin 39 to a bifurcated pawl carrier 40 whichis pivotally mounted at its lower end to a bracket 41 secured to aprojection 42 on the side plate 1 by a pin 43. The pawl carrier has afirst drive pawl 45 pivotally mounted on the pawl carrier 40 by a pin 46and a hold pawl 47 pivotally mounted on the pin 43. A pair of springs 48and 49 extend between lugs 50 and 51 on the pawl carrier, respectively,and ends of pawls 45 and 47, respectively, so as to urge the pawlstoward a ratchet wheel 52 which is fixed to the drive shaft 27.

A wheel drive sprocket 53 is formed integrally with the ratchet wheel 52and drivingly engages a chain 54 which engages driven sprockets 55 and56 on the axles 5 and 6, respectively. An idler 57 adjustably mounted onthe side plate 1 controls the tension on the chain 54.

A second drive pawl 69 extends rearwardly from and is mounted on thepivot pin 46 and has an inwardlydirected end 61 positioned forengagement with the ratchet wheel 52. The latter pawl is urged towardsthe ratchet wheel by a spring 62 connected between the pawl and a lug 63formed on the projection 42.

The second drive pawl is optionally usable when it is desired to doublethe trenching rate of movement for the machine since the ratchet wheelwill be indexedby pawls in both directions of pawl carrier movement. Innormal operation, the drive shaft 33 through the Cal crank rod causesoscillation of the pawl carrier 40 to impart a throw to the drive pawl45 and also the second drive pawl 60, if it is used, so that, in onedirection of movement the pawl 45 steps the ratchet wheel one tooth andin the other direction of pawl carrier movement the pawl 60 steps theratchet wheel one tooth. The hold pawl 47 does not have any throwimparted thereto and only functions as a hold pawl to prevent retrogrademovement of the ratchet wheel.

A manually operable control member 76 extends from a position adjacentthe rear of the machine toward the front thereof and is pivoted on theside plate 1 at 71 and has the arms 72, 73 and 74 which control thepositioning of the drive and hold pawls with respect to the ratchetwheel 52.

When the handle member 70 is in its uppermost position as shown indotted lines in Fig. 1, the arms 72, 73 and 74 are positioned so thatall three pawls or two, depending upon the optional use of drive pawl 60may be urged into engagement with the ratchet Wheel 52 by the springs48, 49 and 62. In this position of the member 70, the machine willoperate to produce a trenching rate of movement of the machine whichisthat rate of movement desired when forming a trench.

In the middle position of the handle 70, as shown in full lines in Fig.l, the drive pawls 45 and 66 are held out of engagement with the ratchetwheel 52 but the arm 73 is so positioned that the hold pawl 47 may stillengage the ratchet wheel. This position of the pawl mechanisms functionsto lock the machine against movement when the trench cutting mechanismis lowered into the ground.

The lowest position of member 70 (Figs. 1 and 4) rcsults in additionallymoving the hold pawl 4-7 out of engagement with the ratchet wheel 52 sothat the pawls have no effect on the ratchet wheel 52 which permits themachine to move in a mobile rate of movement as caused by mechanismhereinafter described. The term mobile rate of movement is meant to meana rate of movement greater than the trenching rate of movement and is arate of movement desired when the machine is moved under its own powerbetween cutting locations.

The mobile rate of movement for the machine is obtained by means of apin (Fig. 9) which extends through and connects the sleeve 26 to thedrive shaft 27 so that the rotation of the pulley 22 is directlytransmitted to the wheel drive sprocket 53 through the shaft 27. The pin80 is held in connecting relation with sleeve 26 and shaft 27 by aspring clip 31 which surrounds the sleeve 26. It will be noted that thedirection of movement imparted to the machine when in mobile drive withthe pin 8%) in use is opposite to that when the machine is in trenchingrate of movement under operation of the pawl 45.

A pair of spaced-apart boom plates 91 and 91 lie adjacent the innersides of the side plates 1 and 2 and are pivotally mounted on sleeves92: and 93 which extend inwardly through the side plates and the boomplates. The sleeves 92 and 93 are secured to the outer sides of the sideplates by bolts as indicated at 4 and 95 and form bearing supports fordrive shaft 33. The boom plates 90 and 91 have a cross plate 96 extendedtherebetween and secured thereto which has a threaded stub shaft 97secured thereto by a plurality of angle brackets 98. These parts may besuitably secured together as by welding.

A boom 100 in the form of a tubular rod is slidably mounted on the stubshaft 97 and keyed thereto as shown at 101 to prevent rotation of theboom with respect to the stub shaft. A nut 102 is threadedly mounted onthe stub shaft and abuts the end of the boom so that the boom may beshifted along the stub shaft for a purpose more fully describedhereinafter. The boom 100 has a guide sprocket 103 at its outer end andidler sprockets 104 and 105 which guide an endless cutter chain 106which passes along the upper and lower sides of the boom.

. thereto.

This chain is provided with cutters 107 spaced along the length thereof.The cutter chain is driven by a drive sprocket 108 keyed to the driveshaft 33 and located between the ends of sleeves 92 and 93 upon whichthe boom plates and 91 are pivotally mounted.

A pair of propelling members and 111 are fixed to a shaft 112 rotatablymounted in a pair of ears 113 and 114 depending from a collar 115 whichis adjustably secured to the inner end of the boom by friction bolts 116and 117. The propelling members 110 and 111 are positioned generallybelow and at opposite sides of the boom 100 so that when the boom islowered in cutting a trench, as shown in Fig. 2, the propelling membersfunction to receive the material elevated from the trench and form itinto piles to prevent its returning into the trench as well as to throwit into the path of paddles referred to hereinafter.

A propeller drive sprocket 120 is keyed to the shaft 112 and thepropeller drive sprocket is engaged by the cutter chain 106 to causerotation thereof.

A paddle frame extends outwardly from each of the boom plates andcomprises a rod 121 extending outwardly at an angle from the associatedboom plate and secured The outer end of the rod is connected to a barformed of parts 122 and 123 which are slidably adjustable with respectto each other and held in fixed relation by a friction bolt 124. Anidler sprocket 125 is carried on the part 123 and a drive sprocket 126is carried on the part 122. A paddle chain 127 passes around thesprockets and carries paddles 128 for carrying dirt outwardly away fromthe propelling members 110 and 111. Both of the paddle frame and chainmechanisms are identical so that similar reference numerals are used inconnection with both of these units.

The drive for the drive sprockets 126 is obtained from a primary drivesprocket 130 which is keyed to a paddle drive shaft 131 extendingthrough the upper forward ends of the boom plates 90 and 91 androtatably mounted therein by collar and bearing units 132 and 133. Theouter ends of the drive shaft 131 are connected to the drive sprockets126 by a pair of universal joints 134 and 135. The primary drivesprocket 130 is positioned above the cutter chain 106 and is engaged onits underside by the cutter chain so as to receive power therefrom.

As shown in Fig. 1, the boom 100 is in an elevated position to enablemovement of the machine between cutting positions and at the mobile rateobtained by use of the pin 80 (Fig. 9). The boom is shown in a loweredposition in Fig. 2 and it will be appreciated that the angle of the boomwith respect to the body of the machine may be less than that shown if ashallower trench is desired. The position of the boom with respect tothe body of the machine is obtained by a handle which is connected to athreaded shaft 141 secured against longitudinal movement in a frame 142by collars 143 and 144. A collar is threadably mounted on the shaft 141and has ears 156 and pin 156a which confine therebetween a cross rod 157extended between and secured to the rear ends of the boom plates 90 and91. The frame 142 is pivotally mounted at its lower end on the crossbrace 4 through which the axle 5 extends. Depending upon the directionof rotation of the handle, the boom will be either raised or lowered bypivoting of the boom plates 90 and 91 on the sleeves 92 and 93.

The endless cutter chain 106 has an added function of holding the boom100 on the stub shaft 97 since the chain extends around the guidesprocket 103 on the free end of the boom and around the drive sprocket108. The cutter chain may be maintained taut by working the nut 102outwardly on the stub shaft which shifts the boom outwardly. One of theimportant features of this invention is that the boom may be readilyremoved from the machine by shifting the nut 102 towards the cross plate96 to slack the chain 106 sufficiently so that it may be taken off theguide sprocket 103 which results in freeing the boom-for release fromthe stub shaft. This fea ture also results in permitting differentlengths of boom to be used with the machine depending upon the depth oftrench that is to be made and only additionally requiring a suitableshortening of the cutter chain.

The removability of the boom along with removability of the handles 12and 13 substantially reduces the overall length of the machine so thatit may be transported from one location to another by placing it on arelatively small truck. The machine may be placed on thetruck under itsown power.

The boom 100 at its outer end adjacent the guide sprocket 103 has a rod160 (Fig. 3) extending across the path of the chain to deflect rocks orother debiis away from under the chain so that a rock lodged between thechain and the upper side of the boom will not be carried down toward thesprocket 103 and result in a jam between the chain and sprocket.

When in mobile position, the machine will travel toward the rightlooking at Fig. 1 and when cutting a trench, the machine will traveltoward the right looking at Fig. 2 which is the opposite direction.Looking at Fig. 2, the propelling members 111 and 112 are rotated in acounter-clockwise direction or, in a clockwise direction looking at Fig.5 while the paddle members 128 nearest the ground will movev away fromthe wheels 10. Because of the angular relation of the paddle chains 127with respect to the boom plates, as shown in Figs. 6 and 7, the paddlesmove laterally outwardly from the wheels.

The components of the machine are so arranged that with the boom 100 inits upper position as shown in Fig. 1, the machine is substantiallybalanced about the front axle 5. The wheels 10 on the front axle 5 aredetachably connected thereto by pins, one of which is indicated at 165,which extend through hub 16511 of the Wheels 10 and an opening 2165bformed in the end of the axle. Each pin is held in connecting positionby a clip member 166 which substantially surrounds the wheel hub. Asshown in Fig. 11, the wheels 10 on the rear axle 6 are secured theretoby pins 169 and held by cotter key 170.

With the machine balanced about the front axle 5, and the front wheelsdisengaged from their axle, the machine may be moved along at a mobilerate by the drive through the rear axle 6 and when it is desired tochange the direction of movement of the machine, the rear wheels may belifted off the ground and a turn easily made. A pair of collars 167 and16% hold the wheels in on the front axle.

I claim:

1. A trenching machine comprising, a body having spaced-apart sideplates, ground-engaging wheels rotatably mounted on said body, a pair ofboom plates lying adjacent the inner sides of said side plates andpivotally mounted thereon, a cross plate extended between the boomplates and secured thereto, a stub shaft extending forwardly from saidcross plate, a boom re movably mounted on said stub shaft and extendingforwardly therefrom, a pair of propelling members positioned below andat each side of the boom and mounted on the boom adjacent the stub shaftfor piling up material, a pair of paddle frames associated one with eachof said boom plates and lying out-board of the propelling membersincluding a rod extending outwardly at an angle from each boom plate, adrive sprocket and a guide sprocket mounted on each paddle frame, achain carrying paddles extended around the sprockets on each of saidframes so as to carry material away from said propelling members, apaddle drive shaft extending through said boom plates for driving thedrive sprockets on said paddle frames, a primary drive sprocket for saidpaddle drive shaft located between the boom plates, a primary drivesprocket for the propelling members located between said propellingmembers, and an endless cutter chain disposed on the boom for cutting atrench and positioned to engage said primary drive sprockets to rotatethe propelling members and move the paddles.

2. A trenching machine comprising, in combination, a body havingspaced-apart side plates, a pair of boom plates lying adjacent the innersides of said side plates and pivotally mounted thereon, a cross plateextended between the boom plates and secured thereto, a boom removablysecured to said cross plate and extending forwardly therefrom, a pair ofpropelling members positioned below and at each side of the boom forpiling up material, a pair of paddle frames associated one with each ofsaid boom plates and lying outboard of the propelling members, a drivesprocket and a guide sprocket mounted on each paddle frame, a chaincarrying paddles extended around said sprockets so as to carry materialaway from said propelling members, a paddle drive shaft extendingthrough said boom plates for driving the drive sprockets on said paddleframes, a primary drive sprocket for said paddle drive shaft locatedbetween the boom plates, a primary drive sprocket for the propellingmembers located between said propelling members, and an endless cutterchain carried on the boom for cutting a trench and positioned to engageand drive said primary drive sprockets.

3. A trenching machine including, a body, a boom extending from one endof: the body, means mounting the boom for up and down movement, anendless cutter chain on the boom, a pair of propelling memberspositioned beneath and at opposite sides of the boom end adjacent thebody for piling up and throwing outwardly material that is elevated bythe cutter chain, a pair of driven chains carrying paddles locatedoutboard of said propelling members, there being one at each side of theboom for transporting material away from the area of the propellingmembers, and means mounting the propelling members and driven chains formovement with the boom.

4. A trenching machine including, a body, a boom extending from one endof the body, a cutter chain on the boom, a pair of propelling memberspositioned beneath and at opposite sides of the boom end adjacent thebody for piling up material that is elevated by the cutter chain, a pairof driven chains located outboard of said propelling members and at anangle with respect to the boom, there being one at each side of theboom, and paddles spaced along the driven chains for transportingmaterial away from the area of the propelling members.

5. A portable trenching machine, including a body having a pair of axlesadjacent the ends of the body and wheels thereon, a boom extending froman end of the body, a cutter chain on said boom, lateral conveyingmechanism adjacent said end of the body, handles extending from theother end of the body, a motor on said body adjacent the latter end,disengageable means for connecting the wheels associated with the frontaxle adjacent the boom thereto for rotation therewith, and means fordriving the rear axle adjacent the handle end of the body, the partsbeing positioned so that the machine may be tilted about the front axleso as to raise the wheels on the 8 rear axle and permit steering of themachine by independent rotation of the wheels on the front axle upondisengagement of said connecting means.

6. A trenching machine including a body formed of spaced-apart sideplates, a pair of boom plates lying adjacent said side plates, meanspivotally mounting the boom plates intermediate their ends on the sideplates, a first cross brace extending between and secured to one of theends of said boom plates, a tubular cross brace extending between andsecured to the side plates beneath said first cross brace, manuallyoperable means connected between the first cross brace and the tubularcross brace for pivoting the boom plates with respect to the body,wheels on said body for movably supporting the machine, and an axle fortwo of said wheels extended through the tubular cross brace.

7. A self-contained walking-type trenching machine including, a body, aplurality of ground engaging wheels supporting said body for movementalong the ground, a pair of spaced apart rotatable axles mounted on saidbody in fixed relation thereto for supporting said wheels, a boom mountswingably secured to one end of the body, a boom on said mount extendingin a direction away from the body, an endless chain carrying spacedcutters extended around the boom with a lower reach on the underside ofthe boom, means for raising and lowering the boom relative to the bodybetween a downwardly angled trenching position and an upper position andfor maintaining said boom in either of said positions, movable meanspositioned adjacent the upper end of the lower chain reach when the boomis in its downwardly angled trenching position for preventing materialdelivered from the trench from falling back therein and for conveyingmaterial laterally away from the trench, a handle for steering saidmachine connected to and extending outwardly from the end of the bodyopposite from said boom, selectively operable means for driving certainof said wheels for moving the machine along the ground, and a drivemotor on said body operatively connected to said wheel driving means,said endless chain and said material conveying means to provide powerfor movement thereof.

8. A self-contained walking-type trenching machine, as defined in claim7, including manually operable means for removably connecting the handleand boom to the body, whereby the boom and handle may be removed tosubstantially reduce the length of the machine.

References Cited in the file of this patent UNITED STATES PATENTS 99,016Slater Jan. 18, 1870 1,635,623 Holmes July 12, 1927 2,341,883 Sloan Feb.15, 1944 2,519,075 Schmidt Aug. 15, 1950 2,519,077 Schmidt Aug. 15, 19502,584,287 Przybylski Feb. 5, 1952 2,598,768 Donald June 3, 19522,714,262 Malzahn Aug. 2, 1955 2,751,698 Brown June 26, 1956

